Research on land cover change and its ecological effect on lower reaches of Lancang River - A case of Xishuangbanna, Yunnan Province, China

Land use and land cover change directly impacts biological diversity worldwide, contributes to climate change, and affects the ability of biological systems to support human needs by altering ecosystem services. In this paper According to Xishuanabanna' s land cover characteristic and ecosystem type, the land cover category of the region was divided into six classes, including cultivated land, woodland, grassland, water area, constructed land and disused land. TM images in 1985,1995 and 2000 were used to identify the changes of land cover at the region. Firstly, linear spectral unmixing method was used to map the boundary of land cover category in ERDAS 8.7. Secondly, the dynamic information of the land cover change in the last 15 years was calculated by the map algebra in ARCGIS 9.0. Thirdly, based on the theory of ecosystem service function and the service function value of global different ecosystem provided by Costanza et it, the value of the six land cover categories in Xishuangbanna was worked out. Finally, ecological environment effect that the regional land cover change produced in study period was calculated